1. Technical Field
Embodiments of the present invention described herein relate generally to the appraisal of various weather hazards, including but not limited to such hazards as they affect air, ground, and water travel.
2. Description of Related Art
Weather has long been known the affect travel, including air, ground and sea travel. It has also long been known to attempt to better understand current and forecast weather data in order to provide for safer and more efficient travel for recreational and professional consumers.
Weather is a very complex phenomenon, and the descriptions of its various components are generally produced by people with an intimate knowledge of the subject. This can often lead to confusion for the end user whose familiarity with the various components varies widely. The consumers of this data include all segments of society including recreational and professional consumers.
The descriptors for weather often can be confusing to users who do not have an in depth knowledge of the various components. For example in convective weather descriptions, there are many different scales for the various hazards resulting from the storm. For radar, there are several scales for the reflectivity (dBz) depending on the mode of the radar. There are also varying scales for rainfall amounts, lightning, icing and turbulence. Business and general aviation can struggle with this widely varying array of products.
A significant focus of this discussion will be upon aviation, but the tools can address the shortcomings in other areas such as marine and ground transportation since the goal of an intuitive, straightforward approach is similar across the user population.
Aviation
Atmospheric turbulence has plagued aviation since its earliest days. Pilots, air traffic controllers, and airline dispatchers have officially relied on pilot reports (PIREPs) of hazards such as turbulence, icing, etc., to ascertain both its location and severity. Although PIREPs are firsthand accounts of actual pilot experiences, they have by their very nature limitations. Each pilot's interpretation of a given encounter with turbulence may vary widely, and reports are generally few. According to some research, the average difference between the actual location of a turbulence encounter and the reported location of the same encounter as contained in a PIREP is 135 km. They can also be very aircraft-dependent; a pilot's report of his aircraft reaction relative to the current atmospheric state can be very different in a regional jet compared to an Airbus 380.
In addition, the relatively few PIREPs recorded are often broadcast too late to avoid similar encounters by nearby or trailing aircraft. In the context of the modern air traffic system and air carrier operations, the shortcomings of turbulence related PIREPs have significant consequences in three main areas.
Probably most obvious among these is the realm of aviation safety. The lack of real time, objective turbulence data for pilots, dispatchers and controllers in an area where unexpected turbulence is present can lead to unnecessary and sometimes unsafe turbulence encounters for multiple aircraft, whereas the presence of better defined data could lead to mitigation or avoidance tactics and far fewer cabin injuries. While the robust structural standards to which airliners are now manufactured provide adequate structural safety margins for the aircraft, it is essential that crews are able to alert the passengers and crew to ensure their safety.
Pilots and air traffic controllers also know intuitively that the imperfections of conventional turbulence reporting adversely affect airspace capacity, (the second main reason), particularly with respect to the utilization of en route altitudes. For a better understanding of how this is possible, consider the following scenario which, though the flight is hypothetical, is borne out thousands of times each day within the National Airspace System (NAS). The pilots of Flight 123, a regional jet, report moderate turbulence at their flight planned altitude of Flight Level 330 (FL330) and are given clearance to descend to FL290 for a better ride. Due partly to the subjective nature of reporting, imagine that the level of the turbulence encountered was actually only light and would have been of very short duration. Consider also that what might have been light turbulence for the regional jet would have been an even lesser level for larger airplanes transiting the same area. But because data in this airspace is inadequate both quantitatively and qualitatively, word of moderate turbulence at FL330 is propagated often for hours, resulting in the potentially significant underutilization of en route airspace.
The reality of day-to-day operations, however, reveals a problem of much greater magnitude, as conscientious users in a given area routinely avoid numerous en route altitudes just for light turbulence. Although pilots, controllers, and dispatchers speculate as to the pervasiveness of this phenomenon, their suspicions are in fact supported by flight data. Preliminary studies show approximately 30% of flights will leave their flight level within 5 minutes of an initial encounter with turbulence of 0.2 g or higher. A subset of these changes were either appropriate for the level of turbulence encountered or the result of an air traffic control clearance unrelated to the turbulence, but it is also reasonable to assume that a good percentage of these changes were due to the light turbulence alone. It is also worth noting that these data do not account for the number of flights that never achieved the most efficient flight planned altitude due to mere rumors of turbulence over the ATC frequency.
Although airline dispatchers work diligently to arrive at the best compromise of ride comfort and economy in generating flight plan cruise altitudes, they lack accurate objective data to aid in their decisions due to the above issues. Even when they are able to provide good recommendations, such efforts are routinely and unnecessarily undermined by the repeated occurrence of the above scenario.
Of course, all of this maneuvering has yet a third consequence in that it significantly reduces airline fuel economy and increases carbon emissions. For all major U.S. carriers, it is estimated that jet fuel wasted annually due to these inefficiencies could be in the hundreds of millions dollar range. Though expensive in its own right for airlines, wasted fuel also has significant social and environmental costs in the form of excessive carbon emissions, as well as delay costs for the traveling public via the overall poor allocation of airspace. These inefficiencies exacerbate the challenges to commerce presented by stubbornly high energy prices, which are now being borne by air travelers in the form of fuel surcharges and higher ticket prices.
The present system for handling initial flight plans and any subsequence changes called reroutes is very labor intensive, especially with changes due to weather. For a typical commercial flight, a licensed dispatcher in the airline's operational center files a flight plan electronically using a tool that gives the optimal path based on the business model of the corporation and the time of departure. If there are no constraints, the air traffic system will respond with a clearance that is received by the airline and entered into the air traffic control computers. If there are any changes needed, the airline and the air traffic provider negotiate the changes acceptable to both parties. In a dynamic weather situation, this process can be tedious and cumbersome often resulting in delays. The arrival times are dependent on these delays and often result in a long string of aircraft based on first come first served in the arrival sequence.
Marine and Ground Transportation
The use of weather in the marine and ground transportation segments can vary even more than aviation because of the wide range of user background and experience. Many users have no training in weather basics or the products produced by the governing agencies.
Different Hazards
Producers of weather hazards include convective activity, hurricanes, and sandstorms.